Balloon valve adapter



FIG. 1 is a front isometric view of a balloon valve adapter, showing my new design;

FIG. 2 is a front view thereof.

FIG. 3 is a back view thereof;

FIG. 4 is a right side view thereof;

FIG. 5 is a left side view thereof;

FIG. 6 is a top view thereof; and,

FIG. 7 is a bottom view thereof.

The broken lines in FIGS. 1-7 are for the purpose of illustrating the replaceable cover top and form no part of the claimed design. 

CLAIM The ornamental design for a balloon valve adapter, as shown and described. 